
9
3-3 Description of Terminals
Terminal symbol (code) Functional descriptions
Terminals for three-phase AC input 415V
Terminals for Single-phase AC input 220V
Output terminals, connect with three-phase AC electromotor
Terminals for braking resistor(optional)
Terminal of ground (Earth terminal)
R, Y, B
L,N
U, V, W
B1, B2
For safety's sake, please connect wires according to the regulations of National Electrical Code while
proceeding wiring.
3-3-1 Connection of Input Power Terminals
An additional breaker/chopper must be connected in series with the terminals of the major loop (R,
Y, B or L, N and U, V, W). For better running, an electromagnetic contactor should be connected with
them in series so that it could cut off the power while the protection function of the converter is activated
(Tip: R-C surge absorbers should be added to the ends of the electromagnetic contactor). If an additional
earth leakage circuit breaker (ELCB) is installed as a protective device for electric leakage, the sensitivity
of current should be more than 200mA while actuation time should be no less than 0.1 second to prevent
ELCB from malfunctioning. AC reactor must be connected with the input terminals in cases were the
rectifiers could be damaged by high-voltage and high-current input from the grid, which could also
improve the input power factors. Do not control the converter by disconnecting the major loop. Instead of
that, RUN/STOP buttons on the keyboard or control loop terminals should be applied to the control of the
converter; if it has to be controlled by that way, it can be implemented only once every one hour. It's
feasible to reduce the interference with devices nearby by connecting an additional noise filter with the
input terminals. Do not connect converter driven by three-phase power to single-phase source.
3-3-2 Connection of Output Power Terminals
Output terminals must be connected to the three-phase motor in the correct order; if the motor
rotates in the wrong direction, any two wires among U, V and W electrical wiring can be switched with
each other. In any case, do not connect output terminals to a phasing capacitor or surge-absorber. When
the length of wire connecting converter with motor is more than 50 meters, there may be a large amount
of electric leakage caused by the capacitors between the wiring, which may lead to over current;
additionally, to protect the insulation of motor from being damaged, an additional output reactor must be
installed. An additional noise filter can be installed to reduce the electromagnetic interference of output if
surroundings can be easily affected by the converter; interference can also be minimized by reducing its
carrier frequency.
User Manual